HBO officially confirmed Rachel McAdams will join Colin Farrell and Vince Vaughn for the second season of "True Detective," according to The Hollywood Reporter.

She will fill the only female lead among the four main parts on the Emmy-winning series. HBO also confirmed Taylor Kitsch's leading role after the "Friday Night Lights" star all but confirmed the casting to Adweek last month. Kelly Reilly also joins the cast.

McAdams remained the frontrunner for the role throughout much of casting with "Mad Men" star Elisabeth Moss and Jessica Biel also considered. HBO confirmed Farrell and Vaughn's roles in September.

Production has begun on the eight-episode season set to film around Los Angeles. Creator Nic Pizzolatto once again wrote each episode, but the episodes' direction will be split up among "Fast & Furious" director Justin Lin and others.

The story revolves around three police officers and a career criminal who must navigate a web of conspiracy in the aftermath of a murder. Farrell, McAdams and Kitsch will play the officers, each from different departments around Los Angeles.

Farrell will star as Ray Velcoro, a compromised detective whose allegiances are torn between his masters in a corrupt police department and the mobster who owns him, according to HBO. McAdams' character Ani Bezzerides is a Ventura County sheriff's detective whose uncompromising ethics put her at odds with others and the system she serves.

Kitsch will play Paul Woodrugh, a war veteran and motorcycle officer for the California Highway Police who is running from a difficult past and the sudden glare of a scandal that never happened.

Vaughn will take on the role of Frank Semyon, a career criminal in danger of losing his empire when his move into legitimate enterprise is upended by the murder of a business partner. Reilly will play his wife, a former D-list actress who is a full partner in his enterprises and ambitions.

HBO didn't give an official premiere date but it will most likely debut next summer.